Intraoperative hypothermia remains a frequent and under-recognized complication in neonates undergoing surgery despite standard preventive measures. Low-flow anesthesia, by increasing rebreathing and conserving heat and humidity, may offer a thermo-protective effect. In this study, we compare the incidence of intraoperative hypothermia between low-flow (1 L/min) vs. routine-flow (2 L/min) anesthesia in neonates undergoing abdominal surgery. After obtaining written informed consent from parents or legal guardians, 160 neonates scheduled for elective or emergency abdominal surgery were randomized into two groups: Group L (low-flow, 1 L/min) and Group C (control, 2 L/min). Core temperature was continuously monitored intraoperatively. The primary outcome was the incidence of intraoperative hypothermia (core temperature < 36°C). Secondary outcomes included changes in core temperature, minimum and maximum intraoperative temperature, percentage of surgical time spent under hypothermia, time to extubation, blood loss, transfusion requirements, use of inotropes, and postoperative ventilation. The incidence of intraoperative hypothermia was significantly lower in group L compared to group C (75% vs. 90%, p = 0.01). The median (IQR) drop in core temperature from baseline was smaller in group L as compared to group C [0.80°C (0.60-1.10) vs. 1.20°C (0.90-1.50), p < 0.001]. Minimum core temperature was higher in group L [35.5°C (35.20-35.90) vs. 35°C (34.80-35.40), p < 0.001]. The percentage of surgical time spent under hypothermia (< 36°C) was significantly lower in group L [50.3% (95% CI: 43.3-57.3)] compared to group C [65.6% (95% CI: 58.6-72.6), p = 0.003]. While intraoperative blood loss was slightly higher in the low-flow group, the clinical impact was minimal. Other outcomes, including extubation time, inotrope use, and hypoxia incidence, were comparable between groups. Low-flow anesthesia technique at 1 L/min is a safe and effective approach for reducing the incidence and duration of intraoperative hypothermia in neonates undergoing abdominal surgery. Clinical Trial Registry of India (www.ctri.nic.in): CTRI/2022/11/047532.

The effects of heat exposure on dynamic cerebral autoregulation (dCA), the capacity of the cerebrovasculature to buffer rapid changes in arterial pressure, and its directional sensitivity, defined as the asymmetric cerebrovascular response to increases versus decreases in mean arterial pressure (MAP), remain incompletely understood. This uncertainty is largely attributable to concomitant heat-induced reductions in arterial carbon dioxide. We hypothesized that moderate isocapnic hyperthermia would impair dCA, particularly at higher frequencies of MAP oscillations, while preserving directional sensitivity across thermal conditions. Twenty healthy young participants (9 females, age: 24 ± 5 yrs) completed oscillatory lower body negative pressure trials at 0.05 and 0.10 Hz under normothermic and hyperthermic (core temperature +1.0°C) conditions. End-tidal carbon dioxide partial pressure (PETCO2) was clamped at baseline using a computer-controlled gas delivery system. Middle cerebral artery mean blood velocity (MCAvmean), MAP, PETCO2, heart rate, and core temperature were continuously recorded. dCA was assessed using transfer function analysis (TFA), and directional sensitivity was quantified using time-adjusted absolute (∆MCAvmeanT/∆MAPT) and relative (RelMCAvmeanT/RelMAPT) metrics. Moderate isocapnic hyperthermia increased TFA coherence at both frequencies and selectively impaired dCA at 0.10 Hz, as evidenced by increased TFA gain and normalized gain. Directional sensitivity was present at 0.05 Hz, indicated by higher ∆MCAvmeanT/∆MAPT and RelMCAvmeanT/RelMAPT during MAP decreases compared with increases, but was absent at 0.10 Hz. These findings demonstrate that isocapnic hyperthermia impairs dCA at higher frequency while preserving directional sensitivity at lower frequency, suggesting that distinct physiological mechanisms govern these components of cerebrovascular regulation beyond the influence of carbon dioxide.

Adaptations of the cardiovascular system in hibernating mammals.

Cognitive performance is preserved following rapid heat stress exposure in firefighters.

Impact of a Thermal Care Bundle (Short Prewarming) on Shivering and Thermal Comfort in Osteosynthesis Patients: A Randomized Controlled Trial.

Research note: Cosinor-based rhythmometry reveals how heat stress disrupts the circadian rhythm of core body temperature in broilers.

Core body temperature is associated with visual representations of social group members.

Drinking water temperatures modulate gut microbiota-L-cysteine axis to enhance adipose thermogenesis and alleviate obesity-related metabolic disorders in mice.

Performance of a wearable CORE sensor for nocturnal core temperature monitoring during sleep.

Under-expanded hydrogen jet fires pose a critical safety challenge, yet remain difficult to model with low-Mach CFD solvers. This study compares two strategies for representing the high-pressure jet with Fire Dynamics Simulator (FDS): (i) an Eulerian, notional nozzle inlet based on fully expanded conditions, and (ii) a Lagrangian, momentum-carrying particle source that transfers mass and momentum to the resolved field. Validation against Sandia vertical jet experiments examines flame length, centerline temperature, and radiative heat flux. A systematic parametric study for particle diameter, size distribution, injection offset, and the basis of inlet conditions for the Lagrangian approach quantifies the sensitivities and identifies practical settings that balance accuracy and cost. The Lagrangian approach reproduces the measured flame length evolution and centerline temperatures and matches the reported radiant fraction; the Eulerian case underpredicts core temperature and radiation. Feature-importance analysis isolates injected particle diameter as the dominant control parameter. Grid/cost comparisons indicate a practical compromise at grid size of 0 . 10 m . • Eulerian and Lagrangian CFD of hydrogen jet flames. • Lagrangian method compares favorably against experimental data. • Sensitivity analysis identifies particle diameter as key parameter.

Restrictive transfusion (Hb < 7 g/dL) is recommended for most perioperative patients, but the optimal threshold for those with cardiovascular disease or Hb 7-10 g/dL remains uncertain. The Perioperative Transfusion Trigger Score (POTTS), which integrates adrenaline requirement, FiO2, temperature, and angina history, may standardize decisions and safely reduce transfusions in older non-cardiac surgery patients. This multicenter RCT in two Chinese hospitals randomized patients ≥ 60 years undergoing non-cardiac surgery 1:1 to POTTS or control. POTTS = 6 plus points for adrenaline, FiO2 (to maintain SpO2 ≥ 95%), core temperature, and angina; transfusion when Hb < POTTS. Control followed 2012 AABB guideline (Hb < 7 always transfuse; > 10 not; 7-10 physician discretion). proportion receiving allogeneic RBC transfusion during perioperative period (ITT population). 253 patients (mean age 72.3 years; 67.6% women) were randomized (May 2023-Sept 2025). Baseline Hb similar (median 9.60 vs. 9.50 g/dL). In ITT, transfusion required in 24.00% (30/125) of POTTS vs. 35.94% (46/128) of control (p = 0.038). Transfusion volume did not differ significantly (median 2.50 vs. 3.00 units, p = 0.520). Overall complication rates: 12.80% vs. 8.59% (p = 0.279); one death in control group (0.85%). No significant differences in specific complications. In patients ≥ 60 years undergoing non-cardiac surgery, POTTS-guided transfusion significantly reduced the proportion of patients transfused without increasing complications. This study was registered at http://www.chictr.org.cn (#ChiCTR2300071739).

Impacts of concentrated leachate recirculation on methane production suppression, odorous gas emissions, and salinity accumulation in municipal solid waste.

While bionic electronic skins are essential for multimodal tactile and thermal perception, distinguishing complex topographies with nonarrayed single-point sensors continues to present technical difficulties. In this study, we developed a bionic electronic skin utilizing phase-separated ionogels and a macroscopic triangular geometry to achieve reliable AI-assisted tactile-thermal sensing, where dynamic mechanical stimuli and quasi-static thermal variations can be decoupled in the time domain. By controlling the aggregation of the ionogel's internal polymer networks, we created a flexible substrate where spontaneously formed surface micropatterns enhance pressure sensitivity. The resulting device detects a broad pressure range (0-1500 kPa) and maintains stable performance across 3500 compression cycles. Additionally, the phase-separated network provides the sensor with distinct temperature responsiveness, yielding a thermal index (B) of 2727.5 K and a temperature resolution of 0.1 K near physiological human body temperature. At the device level, replacing conventional square sensing planes with macroscopic triangular geometric optimization enables effective spatial recognition. Because the slanted edges break spatial symmetry, the sensor interacts with aligned Braille dots sequentially and dense physical stimuli are converted into asynchronous temporal signals. Coupling this geometric optimization with a hybrid convolutional neural network and long short-term memory (CNN-LSTM) algorithm enabled a Braille recognition system that reached 99.1% accuracy under laboratory conditions. The synergy of material phase-programming, macroscopic device geometry optimization, and AI-assisted algorithm offers a potential approach for developing multimodal electronic skin systems in dynamic real-world applications.

To determine the physiological demands and their associations with body core temperature (Tc) of tropical recreational runners during mass participation distance running in a warm-humid environment (Dry bulb Temperature: 27.2±0.4°C, relative humidity: 87±2%). 162 individuals participated in a 21km (n=84) or 10km (n=78) race. Participants demographics were recorded in a pre-race questionnaire, and in-race measurements of environmental conditions, heart rate (HR, n=115), Tc (n=102), four-site skin temperature (Tsk, n=34) and fluid balance (n=36) were assessed. Real-time monitoring of HR, Tc and geolocation was conducted via a multi-user dashboard. Race split and finishing times were extracted from official results. Correlation and multiple linear regression analyses were performed between various parameters and peak Tc. Participants achieved peak HR (21km: 183±9(154-209)bpm, 10km: 180±10(156-204)bpm), Tc (21km: 39.4±0.6(38.3-40.8)°C, 10km: 39.3±0.6(38.2-41.1)°C) and Tsk (21km: 34.0±0.6(32.8-35.4) °C, 10km: 33.7±0.8(31.9-35.3) °C). Mean Tc was higher (p<0.05) in 21km (38.7±0.5(37.9-39.8)°C) than in 10km (38.5±0.4(37.2-39.9)°C). Tsk exhibited an 'inverted-U' profile in the 21km but plateaued in the 10km race. Body mass loss was -2.5±1.1(-5.5 to -0.7)% and -1.3±0.7(-2.4 to +0.5)% for the 21km and 10km participants, respectively. Starting Tc (18%), mean HR (13%), Body Surface Area (11%), and average speed (9%), but not age, estimated maximal aerobic capacity nor finishing time, to peak Tc. Recreational runners experienced high cardiovascular and thermal demands. We observed an 'inverted-U' Tsk profile in the 21km race in contrast to a plateau commonly described in laboratory-based findings. Starting Tc, mean HR, Body Surface Area, and average speed were independently associated with inter-individual differences in peak Tc. Real-time monitoring and contributors of peak Tc may inform future development of targeted strategies to optimise safety of recreational populations competing in the heat.

Electric fans are commonly recommended for older adults to reduce heat strain, yet their effects on cardiac autonomic regulation during heat exposure remain unclear. This study examined phase-dependent heart rate variability (HRV) responses to fan use during prolonged heat exposure in older adults. Sixteen participants (6 females; 65-85 yr) completed three 8-h heat exposures (36°C, 45% relative humidity) with fan-generated air speeds of 0, 2, or 4 m/s. Core (rectal) temperature and a 3-lead electrocardiogram were continuously acquired. Based on temporal core temperature responses, heat exposure was divided into Initial Ramp-Up Phase (0-4 h) and Plateau Phase (4-8 h). Core temperature increased from 37.1 (0.3)°C to 38.0 (0.3)°C (P<0.001) during Ramp-Up and remained stable at 38.1 (0.3)°C (P≥0.627) during Plateau Phase. During Ramp-Up, in all conditions, heart rate (HR) increased (P<0.001), while vagally mediated HRV indices including RMSSD, high-frequency power, and CVI decreased (P≤0.001). During Plateau Phase, HR was lower and RMSSD was higher in 2 m/s compared to 0 m/s condition (P≤0.035), while RMSSD and CVI were higher in 2 m/s compared to 4 m/s condition (P≤0.021). We show that HRV responses to prolonged heat exposure in older adults are phase-dependent. Progressive heat storage during Ramp-Up induces HRV responses reflective of vagal withdrawal, regardless of fan use, whereas low-level airflow (2 m/s) during Plateau Phase modestly attenuated reductions in HRV. These findings suggest that the physiological effectiveness of fan use during extreme indoor heat may depend on air flow intensity and temporal progression of heat strain in older adults.

Disturbance, hydrology and nest architecture were evaluated as drivers of reproductive outcomes in West African dwarf crocodiles (Osteolaemus tetraspis) over two breeding seasons (2021–2022) in Delta State, Nigeria. Surveys spanned culturally protected Emu (Ndokwa West LG) and more disturbed Okogbe and Esaba (Ehavbaren and Okpahoro) in Ughelli South LG, recording nest fate, architecture, microclimate and proximity to water; egg morphometrics (three Emu sites) and hatchling measurements (Emu vs Okopahoro/USLG) complemented field data. Non-parametric tests (Mann-Whitney; Kruskal-Wallis with Holm adjustment) and Cliff’s δ quantified differences. A disturbance gradient was evident: Emu showed repeated nest reuse and successful hatching, whereas Okogbe and Esaba showed recurrent failure. Architecture tracked hydrology (Emu-Ndokwa West LG: deeper upper-egg placement/chamber bottoms; Ughelli South LG: greater cavity depth/mound height). Mean core temperature was 36.7 °C; clutches ranged between 15 and 27 eggs. Within Emu, eggs differed significantly among sites; between localities, Okogbe/USLG hatchlings were longer and heavier. Findings indicate that human pressure rather than microhabitat alone dominates nesting vulnerability and hatch success; architecture mitigates flood risk; and maternal traits with microenvironment jointly shape offspring phenotypes. Recommended actions include community co-management and targeted enforcement to reduce disturbance, hydrology aware restoration that treats mound elevation and cavity depth as functional design features, and instrumented monitoring (core temperature, water level, maternal metrics) to anticipate failure thresholds and sustain recruitment in a changing swamp forest mosaic.

Severe accidental hypothermia (core temperature < 28°C) is an infrequent but resource‑intensive emergency department (ED) presentation that requires altered Advanced Cardiac Life Support (ACLS) management, aggressive rewarming, and timely consideration of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Prior to this project, our inner‑city academic ED lacked a standardized approach, contributing to variability in care. We designed, implemented, and achieved ≥ 95% real‑time utilization of a bedside pathway for patients with severe accidental hypothermia. In response to issues identified in the review of a case of severe hypothermia, a multidisciplinary team developed and revised a severe hypothermia pathway through eight Plan‑Do‑Study‑Act cycles. Implementation strategies included an in situ simulation, targeted nursing skills sessions, and interdepartmental case debriefings. From January 2025 to April 2025, cases of severe hypothermia were reviewed. Our primary outcome was pathway utilization; secondary outcomes were staff perceptions, including timely access to VA-ECMO. Our severe hypothermia pathway includes a flowchart alongside a set of cue cards. The flowchart prompts management in three key realms: modified ACLS, rewarming techniques, and prognostication/VA-ECMO. The cue cards guide step-by-step management, including how to access mechanical CPR and VA-ECMO. Key themes included: development of a streamlined pathway, clinical provider education, and improved interdepartmental communication. 100% (6/6) of cases utilized the pathway. Interdisciplinary feedback suggests providers find the pathway to be useful and that it facilitates timely access to consideration for VA-ECMO. A pragmatic hypothermia resuscitation pathway was successfully implemented in our ED, supporting access to VA-ECMO. Our work acknowledges these resuscitations are resource intensive and may disrupt care to other patients. Therefore, cases for VA-ECMO should be carefully selected. Future work includes exploring an ED Code ECMO at our site and a city-wide prehospital VA-ECMO referral pathway.

Heat Stress and Kidney Injury in Taiwanese Farmers: Associations With Renal Artery Resistance and Urinary Acidification.

The purpose of this study was to examine the time course and magnitude of the inflammatory, hepcidin and endotoxin responses evoked by exercise under hot environmental conditions in female athletes. In a randomized cross‐over study design, 13 endurance trained female athletes (age 26 (range: 20–42) years; VO2max 57.7 (53.4, 62.1) mL·kg−1·min−1; mean (95% CI)) completed two exercise sessions on a treadmill at 70% VO2max in hot (35°C and 40% RH) and cool (11°C and 40% RH) environmental conditions. Peak body core temperature during the hot condition was greater than the cool condition (change +2.1°C (1.8, 2.3); +1.0°C (0.8, 1.3); p < 0.01). There were no changes in LPS or TNFα concentrations at any time point. The hot condition had a greater rise in IL‐6 concentration at 1 h post exercise (hot: 1.6 pg/mL (1.0, 2.2); cool: 1.0 pg/mL (0.8, 1.3); p = 0.04). Hepcidin concentrations at 3 h post exercise were greater in the hot condition (hot: 15.1 ng/mL (8.8, 21.3); cool: 7.9 ng/mL (3.5, 12.2); p = 0.03). These data suggest that moderate exercise in a hot environment evokes a greater IL‐6 concentration and hepcidin concentration post exercise than a cool environment without influence of gut permeability.

Global climate change and biological invasions rank among the leading threats to biodiversity. Rising temperatures can promote invasions by favouring ectothermic species capable of maintaining physiological performance across broader thermal ranges, yet comparative evidence in endotherms remains limited. Here, we examined the heat and cold tolerance limits of three (sub)tropical invasive passerine species [common waxbill (Estrilda astrild), red avadavat (Amandava amandava) and yellow-crowned bishop (Euplectes afer)] and three temperate native passerine species of comparable size and ecology co-occurring in the Mediterranean basin [goldfinch (Carduelis carduelis), serin (Serinus serinus) and great tit (Parus major)]. To assess heat tolerance, we exposed individuals to increasing air temperatures (Ta) during summer and measured their resting metabolic rate, evaporative water loss, the ratio of evaporative heat loss to metabolic heat production, and subcutaneous temperature. During winter, we measured cold tolerance as the minimum tolerated Ta (in a helium-oxygen atmosphere) and the associated changes in core temperature. As predicted, invasive species exhibited higher heat tolerance limits than native species, associated with a delayed onset of evaporative responses and higher evaporative scopes under extreme heat. Moreover, invasive species made greater use of facultative hyperthermia. However, cold tolerance limits did not differ significantly between invasive and native species. These results indicate that some invasive songbirds possess enhanced heat tolerance while maintaining comparable cold performance, which may allow them to occupy broader thermal environments than their temperate native counterparts. Our findings highlight that physiology plays a substantial role in the success of invasive endotherms.